Why no running while engine is trimmed up???

[jdeitchler]

I have recently just bought a 1993 Four Winns 18.5 ft, OMC 4.3.
I have used the trim the 4 times I've had it in the water,all the time. Backing out, coming into shore, etc..
Can I really not use the trim at all while running?? I bought the boat, stored with the trim all the way up and it has no cracks in it? What is all the fuss about.. Is it really true, you should never use it, only in the case of emergency? I would really like some professional input.

 

[88wellcraft]

Re: Why no running while engine is trimmed up???

Use trim while running.....Use tilt while trailering beaching etc.....without motor running.

 

[Haut Medoc]

Re: Why no running while engine is trimmed up???

I think that you are confusing 'trim' with 'tilt'.....
But I'm not an OMC guy......​

 

[jdeitchler]

Re: Why no running while engine is trimmed up???

I'm a boating newbie?
Trim or Tilt --- I have no idea?
I only have the little rocker up/down switch on my throtle handle.
Is that a trim or a tilt?

Am I going to be OK, or is my IO unit going to breaking into a 1000 pieces beacuse I'm doing something wrong?

 

[Haut Medoc]

Re: Why no running while engine is trimmed up???

What 88 wellcraft said.......
You should have a gauge that tells you whether you are in the 'red' or 'green'........
Don't operate the engine in the 'red'......
Trim is generally required to get your boat on proper plane.....
Stay out of the 'red' while the engine is running & you will be OK......​

 

[88wellcraft]

Re: Why no running while engine is trimmed up???

I don't have a trim gauge and just one button for both.....while I'm running I can tell if I'm trimming too much by the sound.....besides, usually its just a couple of taps to get it trimmed correctly. Be sure to watch your rpms if you don't have a gauge.

 

[Coors]

Re: Why no running while engine is trimmed up???

I don't know about a 93, but an '88 factory manual says to trim up until it cavitates, then lower a pinch- that is your limit. The senders always fail, and mean zilch.

 

[88wellcraft]

Re: Why no running while engine is trimmed up???

I've never let mine cavitate......too nervous.......just don't wanna start hearin' my cobra flyin' apart

 

[bruceb58]

Re: Why no running while engine is trimmed up???

If you are close to shore, you can bring it up a little...maybe half way but don't run it at anything but idle speeds if you do. At high speeds you an trim the drive up a little to get optimum speed and bow lift.

 

[HT32BSX115]

Re: Why no running while engine is trimmed up???

I have heard this for quite some time here.

I always think back to the 1966 Mark Twain my dad bought new. It had a 150 Mercruiser in it with a Mercruiser #1 drive.


We ALWAYS ran it in gear all the way up. Actually it wouldn't push the boat all the way up so we would lower it just enough to submerge the prop for running in very shallow water.

We (of course) only ran it at idle.

My dad did this from new until he had me pick it up in 1997 then I did it until I sold it in 2005.

Was this supposed to hurt it?

 

[sker crunch]

Re: Why no running while engine is trimmed up???

When you tilt the drive all the way up with the motor running you are putting a serious strain on the u-joints that power the drive and you can also damage your bellows. If you want to do it, go ahead. It's your dime.

 

[HT32BSX115]

Re: Why no running while engine is trimmed up???

Well let's see.....2005 - 1966 = 39 years.

How long can I do it and still not hurt it?

When you tilt the drive all the way up with the motor running you are putting a serious strain on the u-joints that power the drive and you can also damage your bellows. If you want to do it, go ahead. It's your dime.

 

[bruceb58]

Re: Why no running while engine is trimmed up???

Well let's see.....2005 - 1966 = 39 years.

How long can I do it and still not hurt it?

I think your dropping it enough to submerge the prop was ok as long as you were at idle.

 

[88wellcraft]

Re: Why no running while engine is trimmed up???

There's always an exception to the rule...

 

[HT32BSX115]

Re: Why no running while engine is trimmed up???

Well I sort of thought that....It never made any abnormal noise. The boat had over 2000hrs on it when I sold it and the engine was original. I know Dad never replaced the gimbal bearing ..... I think he may have replaced the U-joints in the 80's maybe. I know he let the raw water pump go until it would overheat at idle and then swear it was the thermostat sticking!

I think your dropping it enough to submerge the prop was ok as long as you were at idle.

 

[Don S]

Re: Why no running while engine is trimmed up???

Every year, I also replace a few Alpha, Bravo, and Volvo transom shields and upper drive housings and ujoint assemblies because of running the engine full up, even at idle. Things change over the years.
It always helps to be lucky when you don't know it can hurt things.

 

[HT32BSX115]

Re: Why no running while engine is trimmed up???

Well I am usually not lucky......(I bought a 460 King Cobra didn't I?)


You can bet I won't be running my Bravo III trimmed up past the limit!

Every year, I also replace a few Alpha, Bravo, and Volvo transom shields and upper drive housings and ujoint assemblies because of running the engine full up, even at idle. Things change over the years.
It always helps to be lucky when you don't know it can hurt things.

 

[Don S]

Re: Why no running while engine is trimmed up???

Well I am usually not lucky......(I bought a 460 King Cobra didn't I?)

You really aren't lucky, are you????, more like a "Take this stick and beat me" type quy, aren't you.

 

[HT32BSX115]

Re: Why no running while engine is trimmed up???

Well yeah!


The good thing is I'm just about ready to drop that 454 B-III in the boat and everything "just fits"....I am happy about that.....


I also think I'll pretty much be able to sell most of the Cobra stuff to someone else out there that made the same mistake I made....

Misery of course.....loves company.

You really aren't lucky, are you????, more like a "Take this stick and beat me" type quy, aren't you.